The Collaborative International Dictionary of English v.0.48:

Apoplexy \Ap"o*plex`y\ ([a^]p"[-o]*pl[e^]ks`[y^]), n. [OE.
   poplexye, LL. poplexia, apoplexia, fr. Gr. 'apoplhxi`a, fr.
   'apoplh`ssein to cripple by a stroke; 'apo` from + plh`ssein
   to strike: cf. F. apoplexie. See Plague.] (Med.)
   Sudden diminution or loss of consciousness, sensation, and
   voluntary motion, usually caused by pressure on the brain.
   [1913 Webster]

   Note: The term is now usually limited to cerebral apoplexy,
         or loss of consciousness due to effusion of blood or
         other lesion within the substance of the brain; but it
         is sometimes extended to denote an effusion of blood
         into the substance of any organ; as, apoplexy of the
         lung.
         [1913 Webster]

WordNet (r) 3.0 (2006):

apoplexy
    n 1: a sudden loss of consciousness resulting when the rupture
         or occlusion of a blood vessel leads to oxygen lack in the
         brain [syn: stroke, apoplexy, cerebrovascular
         accident, CVA]

Moby Thesaurus II by Grady Ward, 1.0:

170 Moby Thesaurus words for "apoplexy":
   Jacksonian epilepsy, Rolandic epilepsy, abdominal epilepsy, access,
   acquired epilepsy, activated epilepsy, affect epilepsy,
   akinetic epilepsy, angina, angina pectoris, aortic insufficiency,
   aortic stenosis, apoplectic stroke, arrest, arrhythmia,
   arteriosclerosis, atherosclerosis, atrial fibrillation, attack,
   auricular fibrillation, autonomic epilepsy, beriberi heart,
   blockage, breakup, cardiac arrest, cardiac epilepsy,
   cardiac insufficiency, cardiac shock, cardiac stenosis,
   cardiac thrombosis, carditis, cataclysm, catalepsy, cataplexy,
   climax, clonic spasm, clonus, congenital heart disease, convulsion,
   cor biloculare, cor juvenum, cor triatriatum, coronary,
   coronary insufficiency, coronary thrombosis, cortical epilepsy,
   cramp, cursive epilepsy, diastolic hypertension, diastrophism,
   diplegia, disaster, diurnal epilepsy, eclampsia, encased heart,
   endocarditis, epilepsia, epilepsia gravior, epilepsia major,
   epilepsia minor, epilepsia mitior, epilepsia nutans,
   epilepsia tarda, epilepsy, epitasis, extrasystole,
   falling sickness, fatty heart, fibroid heart, fit,
   flask-shaped heart, focal epilepsy, frenzy, frosted heart,
   grand mal, grip, hairy heart, haute mal, heart attack, heart block,
   heart condition, heart disease, heart failure, hemiplegia,
   high blood pressure, hypertension, hypertensive heart disease,
   hysterical epilepsy, ictus, infantile paralysis,
   ischemic heart disease, larval epilepsy, laryngeal epilepsy,
   laryngospasm, latent epilepsy, lockjaw, matutinal epilepsy,
   menstrual epilepsy, mitral insufficiency, mitral stenosis,
   musicogenic epilepsy, myocardial infarction,
   myocardial insufficiency, myocarditis, myoclonous epilepsy,
   myovascular insufficiency, nocturnal epilepsy, occlusion, orgasm,
   overthrow, ox heart, palpitation, palsy, paralysis,
   paralytic stroke, paraplegia, paresis, paroxysm,
   paroxysmal tachycardia, pericarditis, petit mal,
   physiologic epilepsy, pile, polio, poliomyelitis, premature beat,
   pseudoaortic insufficiency, psychic epilepsy, psychomotor epilepsy,
   pulmonary insufficiency, pulmonary stenosis, quake,
   reflex epilepsy, rheumatic heart disease, rotatoria, round heart,
   sclerosis, seizure, sensory epilepsy, sensory paralysis,
   serial epilepsy, sexual climax, spasm, stony heart, stoppage,
   stroke, tachycardia, tardy epilepsy, temblor, tetanus, tetany,
   throes, thromboembolism, thrombosis, tidal wave, tonic epilepsy,
   tonic spasm, torsion spasm, traumatic epilepsy,
   tricuspid insufficiency, tricuspid stenosis, trismus, tsunami,
   turtle heart, ucinate epilepsy, upheaval, varicose veins, varix,
   ventricular fibrillation, visitation